North Bristol NHS Trust also tweeted a photo of it adding: "Look what we've found at Frenchay Hospital. Is it the latest #Banksy? What do you think? #Frenchay"

Queen Mary did visit Frenchay in 1943 while it was being used by American troops during the Second World War. The final patients based at Frenchay left last week as most of it's work has moved to the new £430 million pound super hospital in Southmead.

So far the stencil of her hasn't been added to Banksy's website. A genuine Banksy called 'Mobile Lovers' was famously put near a youth club at the bottom of the M32 this Spring. An image of that was put on Banksy's site. Another suspected Banksy was recently added to the wall behind a phone box in Cheltenham.